1. Field
The present disclosure relates to a heat exchange type cooling apparatus for a transformer capable of having a light weight and exhibiting a low energy and high efficiency cooling performance.
2. Description of the Related Art
As a capacity of a transformer increases, a heat generation amount increases and a temperature rise becomes large, such that a problem occurs in a voltage transformation efficiency. Therefore, the transformer is filled with a transformer oil so as to prevent a temperature rise due to Joule heat flowing in a coil and is operated at a predetermined temperature by cooling the transformer oil. The transformer oil, which is an insulating oil obtained by fractionalizing and purifying mineral oil, is used for insulation and cooling of the transformer.
A cooling system for the transformer has used several cooling schemes such as a dry self-cooling scheme, a dry wind cooling scheme, an oil-filled self-cooling scheme, an oil-filled wind cooling scheme, an oil-filled water cooling scheme, an oil-filled air cooling scheme, and the like, depending on a capacity thereof.
Among them, the oil-filled self-cooling scheme is a scheme of putting a transformer body in a case in which the transformer oil is fully filled, transferring a heat generated in an iron core and a winding to the case by a convection action of the transformer oil, and dissipating heat to the air by a radiation and a convection in the case, the oil-filled wind cooling scheme, which is a scheme of obtaining a cooling effect by attaching a blower to an oil filled transformer to which a radiator is attached to perform a forced draft, is used in a large capacity transformer, and the oil-filled water cooling scheme is a scheme of cooling the transformer by installing a cooling pipe for an upper insulating oil in the case of the transformer and circulating a cooling water.
Meanwhile, various electric trains include a transformer for supplying a power to a driving motor. The transformer in operation generates a significant heat. Various cooling systems may be applied in order to cool the transformers. However, in the case of a blowing fan scheme that has been mainly used conventionally, a blowing fan having a weight of several hundreds of kilograms is provided to each transformer, such that a weight is excessively heavy and a large installation space is also required. In addition, an energy for operating the blowing fan also has an effect on the entire efficiency.
In addition to the above-mentioned cooling systems, Korean Patent Laid-Opened Publication No. 10-2005-0108508 has disclosed an oil forced cooling apparatus for a transformer using a heat exchange scheme, but does not suggest a circulation pump and a heat exchanger capable of being applied to a field having large vibrations. In addition, since the oil forced cooling apparatus for a transformer disclosed in Korean Patent Laid-Opened Publication No. 10-2005-0108508 includes a compressor and an evaporator for a cooling cycle, an energy efficiency is low.
Korean Patent Laid-Opened Publication No. 10-2007-0075970. has disclosed a cooling apparatus for a transformer using a cooling cycle without a compressor. However, the cooling apparatus disclosed in Korean Patent Laid-Opened Publication No. 10-2007-0075970 uses a liquefied gas based refrigerant having a boiling point less than 95° C. and still includes an evaporator. Therefore, there is a limitation in making the cooling apparatus compact and saving an energy, and does not consider a structure of a heat exchanger capable of improving a cooling performance or a lightness structure.